Automatic dilutor



' Nov. 16, 1965 J. J. SHAPIRO 3,217,761

AUTOMATIC DILUTOR Filed Aug. 6, 19 3 65 l-Ill! h 26 1E ll llll I I 1 wnnumuumm j 1 36 3 4 I! I 2/) H i 1 L f I i 1 5 jug? I I I 1, 37 I I 7,'3 I as l FIE .3 .62

INVENTOR JUST/N J SHAP o ATTORNEY United States Patent 3,217,761AUTOMATIC DILUTOR Justin J. Shapiro, Labindustn'es, 1740 UniversityAve., Berkeley, Calif. Filed Aug. 6, 1963, Ser. No. 300,276 6 Claims.(Cl. 14127) This invention relates to liquid dispensing devices, andmore particularly to a device for performing precise dilutions.

A main object of the invention is to provide a novel and improved devicefor withdrawing a precise amount of a liquid reagent from a supplyvessel and then transferring this precise amount of reagent to anothervessel together with a precise volume of a diluent liquid while at thesame time washing out the delivery portion of the device with thediluent.

A further object of the invention is to provide an improved device forperforming precise dilutions of one liquid with another, said devicebeing simple in construction, being easy to operate, and beingespecially useful for performing precision repetitive dilutions.

A still further object of the invention is to provide an improvedautomatic dilutor for performing precise dilutions of one liquid withanother, said dilutor being of a type which aspirates a precise amountof reagent from a supply vessel and transfers this reagent to anothervessel together with a precise volume of a diluent liquid, the devicebeing economical to manufacture, being easy to check visually for properoperation, and being easy to clean.

A still further object of the invention is to provide an improvedautomatic precision dilutor adapted to be mounted on a bottle or similarvessel containing diluent liquid, having means to withdraw a preciseamount of reagent from a reagent supply vessel, and having means totransfer the reagent, together with a precise amount of diluent liquidto a receiving vessel, the device being provided with means to admitfiltered air into the top of the first-named bottle or vessel whilediluent liquid is being drawn therefrom and having weighted valve meansto isolate the device from the contents of the first-named bottle orvessel while the reagent is being drawn into the device from the reagentsupply vessel.

A still further object of the invention is to provide an improvedautomatic precision dilutor adapted to be mounted on a vessel containingdiluent liquid, having means to draw a precisely measured amount ofreagent from a reagent supply vessel and having means to transfer thereagent, together with a precisely measured amount of diluent to areceiving vessel, the device being arranged to provide an automaticallyair-free system by the provision of means to drive air out of the systemahead of the reagent.

Further objects and advantages of the invention will become apparentfrom the following description and claims, and from the accompanyingdrawings, wherein: I FIGURE 1 is a vertical cross-sectional view, partlybroken away, showing an improved automatic dilutor according to thepresent invention mounted on a diluent bottle.

FIGURE 2 is an enlarged horizontal cross-sectional view takensubstantially on the line 22 of FIGURE 1.

FIGURE 3 is an enlarged side elevational view of the liquid-filledweight member employed to hold the diluent valve of the device of FIGURE1 closed while reagent is being aspirated into the device.

Referring to the drawings, 11 generally designates an improved precisiondilutor constructed in accordance with the present invention. Thedilutor 11 comprises a main tubular barrel 12, of relatively largediameter, of glass,

or other suitable transparent material, the lower end portion of thebarrel being adapted to be sealingly mounted in the neck portion 13 of abottle 14, or similar vessel, containing diluent liquid. Thus, saidlower barrel portion may be provided with an integral circumferentialsealing rib 15 and an internally threaded annular cap 16 may bethreadedly engaged with the externally threaded upper portion 18 of neck13, the rib 15 being received in the cap 16, and resilient deformableannular sealing rings 19 and 20 being provided on the barrel portionimmediately above and below said rib, as shown in FIGURE 1.

Sealingly and slidably mounted in the upper portion of barrel 12 is adiluent dispensing plunger 21 provided at its top end with the squarehead flange 22, off-center relative to the axis of the plunger, andengageable with the outwardly projecting top flange or rim 23 of barrel12 when the plunger is in its lower-most position, as shown in FIGURE 1.A depending rod 24 is rigidly secured to the outermost corner portion ofsquare flange 22, and adjustably mounted on rod 24 is a flanged stopcollar 25 which is engageable with flange 23 to limit upward movement ofplunger 21. Collar 25 is provided with a clamping screw 27 to lock it inadjusted position on rod 24. Collar 25 is provided with the base flange26 which extends adjacent a diluent volume scale 28 inscribed on barrel12, to indicate the volumetric setting of the diluent plunger 21. Thus,the collar 25 may be adjusted on the rod 24 to deliver a predeterminedamount of diluent per stroke from the diluent vessel 14, said volumebeing indicated on scale 28 by flange 26 with the plunger in its fullylowered position, as shown in FIGURE 1.

The plunger chamber, shown at 29, communicates with a reduced tubularconduit 30 formed integrally with barrel 12 and extending downwardlytherefrom. The lower portion of the conduit is further reduced, as shownat 31, and an enlarged conduit portion 32 is provided between thereduced lower conduit portion 31 and the upper conduit portion 30. Theenlarged conduit portion 32 is formed with a frusto-conical seat 33receiving a movable valve ball 34, said valve ball being biaseddownwardly by an elongated sealed vessel 35 substantially filled withheavy liquid material 60, such as mercury, or the like. The vessel 35 isloosely and slidably disposed in conduit portion 32, allowing free flowof liquid therepast. Said vessel is formed with the upper and lowerannular guide ribs 36 and 37, and has a concave bottom recess 38 inwhich the top portion of ball 34 is receivable. Upward movement of theweighted vessel 35 is limited by the provision of an inwardly projectingintegral stop lug 39 formed in the conduit portion 32 and beingengageable with the top wall portion 40 of the hollow vessel 35.

As will be presently explained, the purpose of the weighted vessel 35 isto keep the ball 34 seated in the frusto-conical seat 33 when reagent isbeing aspirated into the device for subsequent delivery and dilution.

A downwardly and outwardly inclined air inlet tube 41 is integrallyformed in the lower portion of barrel 12 immediately below the junctionof the chamber 29 with the reduced conduit portion 30. The tube 41 isadapted to receive a suitable filter device 42 to filter the air drawninto the diluent vessel 14 when diluent is dispensed therefrom, wherebyto protect the diluent in the vessel 14 from contamination.

A horizontal branch tube 43, formed integrally with barrel 12 andcommunicating with the chamber 29, originates at the level of the bottomend of plunger 21 When said plunger is in its lowermost position.Integrally formed with and rising vertically from the outer end ofbranch tube 43 is the reagent aspirating barrel 44, of relatively smalldiameter, containing the aspirating plunger 45. Plunger 45 is formedwith the top operating flange 65 to which is rigidly secured thedepending rod 46. Said rod 46 is provided with the adjustable stopcollar 47 engageable with the top rim flange 48 of barrel 44 to limitthe upward extension of plunger 45. Collar 47 has a locking screw 49 anda bottom indicator flange 50. A reagent intake volumetric scale 51 isinscribed on barrel 44 and the intake volume may be preset by securingthe collar 47 on the rod 46 with the plunger 45 fully lowered, namely,with flange 65 engaging ri-m 48, the preset volume being indicated byflange St} on scale 51.

Integrally formed with the lower portion of barrel 44 is the laterallydirected conduit portion 52 having the depending tip portion 53. Theorigin of the laterally directed conduit 52 is at the level of thebottom end of plunger 45 when said plunger is fully lowered. Below theconduit portion 52 barrel 44 is formed with a frusto conical ball seat54 in which is movably disposed a seal ing valve ball 55. Upwardmovement of valve ball 55 is limited by an inwardly projecting stop lug55 integrally formed in barrel 44 just below the connection to laterallyextending conduit portion 52.

The contained volume of the conduit portion 52 and the tip portion 53 ispreferably greater than the maximum capacity of the aspirating syringedefined by barrel 44 and plunger 45. This preferred volume relationshipprevents the aspirated reagent from ever reaching the aspirating plunger45.

In operation, with the plunger 45 fully lowered in barrel 44 the top 52is immersed in a receptacle containing the reagent to be dispensed anddiluted. The reagent is aspirated into the tip and the conduit portion52 by raising the plunger 45 until collar 47 engages the rim flange 48,thus drawing the preset volume of reagent into the tip 53 and conduitportion 52. The weighted member 35 holds the ball 34 seated during thisstep. The reagent vessel is then removed, and the intended receivingvessel is then placed below the tip 53. The aspirating plunger 45 isthen allowed to fall and is lowered to expel the reagent into thereceiving vessel. The plunger 21 is then raised gently until collar 24engages rim flange 23, drawing the preset volume of diluent from thevessel 14. After a short time, during which valve ball 34 reseats, theplunger 21 is gently depressed all the way, dispensing the diluent intothe receiving vessel and at the same time washing out the outlet tip 53.

The upward stroke of the plunger 21 causes the diluent to flow upwardlypast the weighted valve ball 34, the weight of the member 35 beingovercome because it is the only valve which can open under therelatively large pressure differential created by the vacuum induced bythe relatively large-diameter plunger 21. On the downward stroke ofplunger 21 the diluent is forced past the valve ball 55, and the presetquantity of diluent is forced through conduit portion 52 and tip 53 intothe receiving vessel, at the same time flushing out said conduit portionand tip.

The valve ball 34 does not open when aspirating plunger 45 is raisedbecause of the combination of the hydrostatic head of liquid above thesurface of the diluent in vessel 14 and the weight of the member 35acting downwardly thereon.

Unless the downward stroke of the plunger 21 is particularly forceful,the plunger 45 will not rise. If the plunger 45 should rise, it may besubsequently depressed to obtain the delivery of the desired amount ofdiluent.

For large aspirated volumes of reagent, tubular extensions may beattached to the tip 53 in any suitable manner, for example, by means ofplastic coupling sleeves.

It will be apparent that because of the geometry of the parts, namely,the provision of the diluent pumping plunger 21 arranged in the mannerabove described, air is automatically removed by pumping the plunger,the air being driven out of the system ahead of the reagent. Theweighted valve member 34 provides complete isolation of the diluentinlet valve assembly from the reagent aspirating portion of theapparatus.

While a specific embodiment of a precision dilutor has been disclosed inthe foregoing description, it will be understood that variousmodifications within the spirit of the invention may occur to thoseskilled in the art. Therefore it is intended that no limitations beplaced on the invention except as defined by the scope of the appendedclaims.

What is claimed is:

1. A reagent dilutor comprising an upstanding diluent barrel having areduced tubular lower diluent intake portion, upwardly opening checkvalve means in said intake portion, means to sealingly secure the lowerend portion of said barrel in a diluent container, air intake means insaid lower end portion, a diluent dispensing plunger in the upperportion of said barrel, means adjustably limiting the upward extensionof said diluent dispensing plunger, a branch conduit connected to saidbarrel above said diluent intake portion, an upstanding reagentaspirating barrel connected to said branch conduit, upwardly openingcheck valve means in the lower portion of said reagent aspiratingbarrel, a reagent aspirating plunger in the upper portion of saidreagent aspirating barrel, means adjustably limiting the upwardextension of said reagent aspirating plunger, and a conduit memberhaving a depending tip connected to the lower portion of said reagentaspirating barrel above said last-named check valve means, the volume ofsaid conduit member and tip being larger than the volume of saidaspirating barrel.

2. A reagent dilutor comprising an upstanding diluent barrel having areduced tubular lower diluent intake portion, upwardly opening checkvalve means in said intake portion, weight means acting on said checkvalve means to bias it against opening, means to sealingly secure thelower end portion of said barrel in a diluent container, air intakemeans in said lower end portion, a diluent dispensing plunger in theupper portion of said barrel, a branch conduit connected to said barrelabove said diluent intake portion, an upstanding reagent aspiratingbarrel connected to said branch conduit, upwardly opening check valvemeans in the lower portion of said reagent aspirating barrel, a reagentaspirating plunger in the upper portion of said reagent aspiratingbarrel, and a depending conduit member connected to the lower portion ofsaid reagent aspirating barrel above said last-named check valve means.

3. A reagent dilutor comprising an upstanding relatively large-diameterdiluent barrel having a reduced depending tubular lower diluent intakeportion, upwardly opening check valve means in said intake portion,weight means acting on said check valve means to bias it againstopening, means to sealingly secure the lower end portion of said barrelin a diluent container, air intake means in said lower end portion, adiluent dispensing plunger in the upper portion of said barrel, a branchconduit connected to said barrel above said diluent intake portion, anupstanding relatively small-diameter reagent aspirating barrel connectedto said branch conduit, upwardly opening check valve means in the lowerportion of said reagent aspirating barrel, a reagent aspirating plungerin the upper portion of said reagent aspirating barrel, and a dependingconduit member connected to the lower portion of said reagent aspiratingbarrel above said lastnamed check valve means.

4. A reagent dilutor comprising an upstanding relatively large-diameterdiluent barrel having a reduced depending tubular lower diluent intakeportion, an upwardly opening ball check valve in said intake portion, aweight member engaged on said ball check valve to bias it againstopening, means to sealingly secure the lower end portion of said barrelin a diluent container, air intake means in said lower end portion, adiluent dispensing plunger in the upper portion of said barrel, a branchconduit connected to :said barrel above said diluent intake portion, anupstanding relatively small-diameter reagent aspirating barrel connectedto said branch conduit, up-

wardly opening check valve means in the lower portion of said reagentaspirating barrel, a reagent aspirating plunger in the upper portion ofsaid reagent aspirating barrel, and a depending conduit member connectedto the lower portion of said reagent aspirating barrel above saidlast-named check valve means.

5. The structure of claim 4, and wherein said weight member comprises ahollow vessel containing a relatively heavy liquid.

6. A reagent dilutor comprising an upstanding relatively large-diameterdiluent barrel having a reduced depending tubular lower diluent intakeportion, an upwardly opening ball check valve in said intake portion, aWeight member engaged on said ball check valve to bias it againstopening, said weight member comprising a hollow vessel containing arelatively heavy liquid, means to sealingly secure the lower end portionof said barrel in a diluent container, air intake means in said lowerend portion, a diluent dispensing plunger in the upper portion of saidbarrel, means adjustably limiting the upward extension of said diluentdispensing plunger, a branch conduit connected to said barrel above saiddiluent intake portion, an upstanding relatively small-diameter reagentaspirating barrel connected to said branch conduit, upwardly openingcheck valve means in the lower portion of said reagent aspiratingbarrel, a reagent aspirating plunger in the upper portion of saidreagent aspirating barrel, means adjustably limiting the upwardextension of said reagent aspirating plunger, and a conduit memberhaving a depending tip connected to the lower portion of said reagentaspirating barrel above said last-named check valve means, the volume ofsaid conduit member and tip being larger than the volume of saidaspirating barrel.

References Cited by the Examiner UNITED STATES PATENTS 1,013,448 1/1912Rose 128213 1,138,749 5/1915 Green 141-105 1,269,348 6/1918 Warren l41272,910,981 11/1959 Wilson et al. 218214 FOREIGN PATENTS 907,262 3/ 1954Germany.

LAVERNE D. GEIGER, Primary Examiner.

1. A REAGENT DILUTOR COMPRISING AN UPSTANDING DILUENT BARREL HAVING AREDUCED TUBULAR LOWER DILUENT INTAKE PORTION, UPWARDLY OPENING CHECKVALVE MEANS IN SAID INTAKE PORTION, MEANS TO SEALINGLY SECURE THE LOWEREND PORTION OF SAID BARREL IN A DILUENT CONTAINER, AIR INTAKE MEANS INSAID LOWER END PORTION, A DILUENT DISPENSING PLUNGER IN THE UPPERPORTION OF SAID BARREL, MEANS ADJUSTABLY LIMITING THE UPWARD EXTENSIONOF SAID DILUENT DISPENSING PLUNGER, A BRANCH CONDUIT CONNECTED TO SAIDBARREL ABOVE SAID DILUENT INTAKE PORTION, AN UPSTANDING REAGENTASPIRATING BARREL CONNECTED TO SAID BRANCH CONDUIT, UPWARDLY OPENINGCHECK VALVE MEANS IN THE LOWER PORTION OF SAID REAGENT ASPIRATINGBARREL, A REAGENT ASPIRATING PLUNGER IN THE UPPER PORTION OF SAIDREAGENT ASPIRATING BARREL, MEANS ADJUSTABLY LIMITING THE UPWARDEXTENSION OF SAID REAGENT ASPIRATING PLUNGER, AND A CONDUIT MEMBERHAVING A DEPENDING TIP CONNECTED TO THE LOWER PORTION OF SAID REAGENTASPIRATING BARREL ABOVE SAID LAST-NAMED CHECK VALVE MEANS, THE VOLUME OFSAID CONDUIT MEMBER AND TIP BEING LARGER THAN THE VOLUME OF SAIDASPIRATING BARREL.